Geoship - Geoship is an efficient mobile application that provides you all international eBay search information right on your mobile device.
uBuyFirst - Advanced eBay buying software finds newly listed "Buy-It-Now" items first!
Melltoo - Melltoo is an elegant mobile application that helps you to buy and sell your stuff right on your mobile devices.
UnderMRKT - UnderMRKT is a popular platform that provides instant notification about new and accurate eBay listing items.
Ritchie Bros. - Ritchie Bros.
Gixen - Free online service that places bids (similar to eBay) in the closing seconds.